Yes you can have it in your spellbook.
You simply have to have access to the spell and make the requisite Spellcraft check.
A wizard can also add a spell to her book whenever she encounters one on a magic scroll or in another wizard’s spellbook. No matter what the spell’s source, the wizard must first decipher the magical writing (see Arcane Magical Writings, above). Next, she must spend a day studying the spell. At the end of the day, she must make a Spellcraft check (DC 15 + spell’s level). A wizard who has specialized in a school of spells gains a +2 bonus on the Spellcraft check if the new spell is from her specialty school. She cannot, however, learn any spells from her prohibited schools. If the check succeeds, the wizard understands the spell and can copy it into her spellbook (see Writing a New Spell into a Spellbook, below). The process leaves a spellbook that was copied from unharmed, but a spell successfully copied from a magic scroll disappears from the parchment.
(emphasis mine)
No you can't brew potions.
Brew potion reads:
Benefit
You can create a potion of any 3rd-level or lower spell that you know and that targets one or more creatures. Brewing a potion takes one day. When you create a potion, you set the caster level, which must be sufficient to cast the spell in question and no higher than your own level. The base price of a potion is its spell level × its caster level × 50 gp. To brew a potion, you must spend 1/25 of this base price in XP and use up raw materials costing one half this base price.
(emphasis mine)
Further in the rules for brewing potions:
The creator must have prepared the spell to be placed in the potion (or must know the spell, in the case of a sorcerer or bard) and must provide any material component or focus the spell requires.
(emphasis mine)
You must have sufficient caster level in order to brew the potion both to set the appropriate caster level and to prepare the spell.
